<template>
	<view class="content1" v-if="isShow==1" @click.stop="isShow=0">
		<canvas @click.stop="" :style="{ width: canvasW + 'px', height: canvasH + 'px' }" canvas-id="my-canvas"></canvas>
		<view class="save-btn" @click.stop="saveImage">保存图片</view>
	</view>
</template>

<script>
	export default{
		props:{
			headerImg:{
				type: String,
				default: 'https://fw.xihenet.net/imgs/amimg1.png'
			},
			title:{
				type: String,
				default: '草莓千层蛋糕'
			},
			subTitle:{
				type: String,
				default: '鲜嫩多汁的草莓融合香甜奶油'
			},
			price:{
				type: Number,
				default: 36.89
			},
			abImg:{
				type: String,
				default: 'https://fw.xihenet.net/imgs/amimg1.png'
			},
			isShow:{
				type: Number,
				default: 0
			},
		},
		data(){
			return {
				canvasW: 0,
				canvasH: 0,
				ctx: null,
				qrcode: 'https://fw.xihenet.net/imgs/amimg1.png'
			}
		},
		mounted: function() {
			// 处理小程序 attached 生命周期
			this.__init()
		},
		methods:{
			//显示
			showCanvas(){
				this.isShow = 1
				this.__init()
			},
			//初始化画布
			async __init(){
				uni.showLoading({
				    title: '加载中...',
					mask: true
				})
				this.ctx = uni.createCanvasContext('my-canvas',this)
				this.canvasW = uni.upx2px(550);
				this.canvasH = uni.upx2px(780);
				//设置画布背景透明
				this.ctx.setFillStyle('rgba(255, 255, 255, 0)')
				//设置画布大小
				this.ctx.fillRect(0,0,this.canvasW,this.canvasH)
				//绘制圆角背景
				this.drawRoundRect(this.ctx, 0, 0, this.canvasW, this.canvasH,uni.upx2px(18),'#FFFFFF')
				//获取标题图片
				let headerImg = await this.getImageInfo(this.headerImg)
				let hW = uni.upx2px(500);
				let hH = uni.upx2px(320);
				//绘制标题图
				this.drawRoundImg(this.ctx,headerImg.path,((this.canvasW-hW) / 2),((this.canvasW-hW) / 2),hW,hH,8)
				//绘制标题
				this.ctx.setFontSize(18); //设置标题字体大小
				this.ctx.setFillStyle('#333'); //设置标题文本颜色
				this.ctx.fillText(this.title,((this.canvasW-hW) / 2),(
				((this.canvasW-hW) / 2) + hH + 30))
				//绘制副标题
				this.ctx.setFontSize(14);
				this.ctx.setFillStyle('#858585');
				let sWidth = this.ctx.measureText(this.subTitle).width
				if(sWidth > hW){
					this.ctx.fillText(this.subTitle.slice(0,19) + '...',((this.canvasW-hW) / 2),(
					((this.canvasW-hW) / 2) + hH + 55))
				}else{
					this.ctx.fillText(this.subTitle,((this.canvasW-hW) / 2),(
					((this.canvasW-hW) / 2) + hH + 55))
				}
				//绘制价格
				this.ctx.setFontSize(14);
				this.ctx.setFillStyle('#f54545');
				this.ctx.fillText('￥',((this.canvasW-hW) / 2),(
				((this.canvasW-hW) / 2) + hH + 90))
				this.ctx.setFontSize(18);
				this.ctx.fillText(this.price,(((this.canvasW-hW) / 2) + 18),(
				((this.canvasW-hW) / 2) + hH + 90))
				//绘制虚线
				this.drawDashLine(this.ctx,10,(((this.canvasW-hW) / 2) + hH + 120),(this.canvasW-10),(((this.canvasW-hW) / 2) + hH + 120),5)
				//左边实心圆
				this.drawEmptyRound(this.ctx,0,(((this.canvasW-hW) / 2) + hH + 120),10)
				//右边实心圆
				this.drawEmptyRound(this.ctx,this.canvasW,(((this.canvasW-hW) / 2) + hH + 120),10)
				//提示文案
				this.ctx.setFontSize(12);
				this.ctx.setFillStyle('#858585');
				this.ctx.fillText('长按保存图片到相册',30,(((this.canvasW-hW) / 2) + hH + 150))
				//底部广告
				let BottomAdImg = await this.getImageInfo(this.abImg)
				this.ctx.drawImage(BottomAdImg.path,15,(((this.canvasW-hW) / 2) + hH + 160),175,55)
				//小程序码
				let qrcodeImg = await this.getImageInfo(this.qrcode)
				this.ctx.drawImage(qrcodeImg.path,198,(((this.canvasW-hW) / 2) + hH + 135), 92, 92)
				//延迟渲染
				setTimeout(()=>{
					this.ctx.draw(true,()=>{
						uni.hideLoading()
						// setTimeout(function() {
						// 	uni.canvasToTempFilePath({
						// 		canvasId: 'my-canvas',
						// 		fileType: 'jpg',
						// 		x: 0,
						// 		y: 0,
						// 		width: this.windowWidth * 0.6,
						// 		height: 100,
						// 		destWidth: this.windowWidth * 0.6,
						// 		height: 100,
						// 		success: function(res) {
						// 			////console.log(res.tempFilePath)
						// 			////console.log("--**")
						// 			// this.imgPath = res.tempFilePath
						// 			uni.previewImage({
						// 				current: res.tempFilePath,
						// 				urls: [res.tempFilePath]
						// 			});
						// 		},
						// 		fail: function(error) {
						// 			////console.log(error)
						// 			////console.log("--**1")
						// 		},							
						// 	})
						// }, 100)
					})
				},500)
			},
			//绘制实心圆
			drawEmptyRound(ctx,x,y,radius){
				ctx.save()
				ctx.beginPath();
				ctx.arc(x, y, radius, 0, 2 * Math.PI,true);
				ctx.setFillStyle('rgba(0, 0, 0, .4)')
				ctx.fill();
				ctx.restore()
				ctx.closePath()
			},
			//绘制虚线
			drawDashLine(ctx,x1,y1,x2,y2,dashLength){
				ctx.setStrokeStyle("#cccccc")//设置线条的颜色
				ctx.setLineWidth(1)//设置线条宽度
				var dashLen = dashLength,
				xpos = x2 - x1, //得到横向的宽度;
				ypos = y2 - y1, //得到纵向的高度;
				numDashes = Math.floor(Math.sqrt(xpos * xpos + ypos * ypos) / dashLen); 
				//利用正切获取斜边的长度除以虚线长度，得到要分为多少段;
				for(var i=0; i<numDashes; i++){
				 if(i % 2 === 0){
					 ctx.moveTo(x1 + (xpos/numDashes) * i, y1 + (ypos/numDashes) * i); 
					 //有了横向宽度和多少段，得出每一段是多长，起点 + 每段长度 * i = 要绘制的起点；
				  }else{
					  ctx.lineTo(x1 + (xpos/numDashes) * i, y1 + (ypos/numDashes) * i);
				  }
				}
				ctx.stroke();
			},
			//带圆角图片
			drawRoundImg(ctx, img, x, y, width, height, radius){
				ctx.beginPath()
				ctx.save()
				// 左上角
				ctx.arc(x + radius, y + radius, radius, Math.PI, Math.PI * 1.5)
				// 右上角
				ctx.arc(x + width - radius, y + radius, radius, Math.PI * 1.5, Math.PI * 2)
				// 右下角
				ctx.arc(x + width - radius, y + height - radius, radius, 0, Math.PI * 0.5)
				// 左下角
				ctx.arc(x + radius, y + height - radius, radius, Math.PI * 0.5, Math.PI)
				ctx.stroke()
				ctx.clip()
				ctx.drawImage(img, x, y, width, height);
				ctx.restore()
				ctx.closePath()
			},
			//圆角矩形
			drawRoundRect(ctx, x, y, width, height, radius, color){
				ctx.save();
				ctx.beginPath();
				ctx.setFillStyle(color); 
				ctx.setStrokeStyle(color)
				ctx.setLineJoin('round');  //交点设置成圆角
				ctx.setLineWidth(radius);
				ctx.strokeRect(x + radius/2, y + radius/2, width - radius , height - radius );
				ctx.fillRect(x + radius, y + radius, width - radius * 2, height - radius * 2);
				ctx.stroke();
				ctx.closePath();
			},
			//获取图片
			getImageInfo(imgSrc){
				return new Promise((resolve, reject) => {
					uni.getImageInfo({
						src: imgSrc,
						success: (image) => {
							resolve(image);
							////console.log('获取图片成功',image)
						},
						fail: (err) => {
							reject(err);
							////console.log('获取图片失败',err)
						}
					});
				});
			},
			//保存图片到相册
			saveImage(){
				var that = this
				let image = new Image();
				image.src = 'https://fw.xihenet.net/imgs/amimg1.png';
				image.onload = function() {
				let canvas = document.createElement('canvas');
				let ctx = canvas.getContext('2d');
				canvas.width = image.width;
				canvas.height = image.height;
				ctx.drawImage(image, 0, 0, image.width, image.height);
				// 将canvas转换为图片base64数据
				let base64Image = canvas.toDataURL('image/png');
				// 创建一个a标签模拟点击进行下载
				let a = document.createElement('a');
				a.href = base64Image;
				// 指定下载的文件名
				a.download = 'downloadedImage.png';
				// 触发a标签的点击进行下载
				document.body.appendChild(a);
				a.click();
				document.body.removeChild(a);
				}
								// uni.canvasToTempFilePath({
				// 	canvasId: 'my-canvas',
				// 	fileType: 'jpg',
				// 	x: 0,
				// 	y: 0,
				// 	width: this.windowWidth * 0.6,
				// 	height: 100,
				// 	destWidth: this.windowWidth * 0.6,
				// 	height: 100,
				// 	success: function(res) {
				// 		////console.log(res.tempFilePath)
				// 		////console.log("--**")
				// 		// this.imgPath = res.tempFilePath
				// 		uni.previewImage({
				// 			current: res.tempFilePath,
				// 			urls: [res.tempFilePath]
				// 		});
				// 	},
				// 	fail: function(error) {
				// 		////console.log(error)
				// 		////console.log("--**1")
				// 	},							
				// })
			}
		}
	}
</script>

<style scoped lang="scss">
.content1{
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;
	width:100%;
	height:100vh;
	background: rgba(0,0,0,.4);
	display: flex;
	flex-direction: column;
	justify-content: center;
	align-items: center;
	.save-btn{
		margin-top: 35rpx;
		color: #FFFFFF;
		background: linear-gradient(to right, #FE726B , #FE956B);
		padding: 15rpx 40rpx;
		border-radius: 50rpx;
	}
}
</style>
